Aspartame

E number E951INS 951CAS 22839-47-0

Used as a sweetener — Codex also lists it as flavour enhancer.

Aspartame is an intense sweetener about two hundred times as sweet as sugar, used in diet soft drinks, tabletop sweeteners, chewing gum and yoghurts. Products containing it must carry a warning that it is a source of phenylalanine, for people with phenylketonuria.

Where it is and isn’t permitted

Status of Aspartame by jurisdiction. Every jurisdiction this site covers is listed, including those where the substance does not appear.
JurisdictionStatusScope and limitsCitation
United StatesFood and Drug AdministrationPermitted, with conditions21 CFR 172.804retrieved 2026-09-07
Codex AlimentariusCodex Alimentarius Commission / JECFAPermitted, with conditions

65 food categories

highest permitted level 10,000 mg/kg

Show every food category
  • 01.1.4 Flavoured Fluid Milk Drinks — 600 mg/kg
  • 01.3.2 Beverage whiteners — 6,000 mg/kg
  • 01.4.4 Cream analogues — 1,000 mg/kg
  • 01.5.2 Milk and cream powder analogues — 2,000 mg/kg
  • 01.6.1 Unripened cheese — 1,000 mg/kg
  • 01.7 Dairy-based desserts (e.g. pudding, fruit or flavoured yoghurt) — 1,000 mg/kg
  • 02.4 Fat-based desserts excluding dairy-based dessert products of food category 01.7 — 1,000 mg/kg
  • 03.0 Edible ices, including sherbet and sorbet — 1,000 mg/kg
  • 04.1.2.1 Frozen fruit — 2,000 mg/kg
  • 04.1.2.10 Fermented fruit products — 1,000 mg/kg
  • 04.1.2.11 Fruit fillings for pastries — 1,000 mg/kg
  • 04.1.2.12 Cooked fruit — 1,000 mg/kg
  • 04.1.2.3 Fruit in vinegar, oil, or brine — 300 mg/kg
  • 04.1.2.4 Canned or bottled (pasteurized) fruit — 1,000 mg/kg
  • 04.1.2.5 — 1,000 mg/kg
  • 04.1.2.6 Fruit-based spreads (e.g. chutney) excluding products of food category — 1,000 mg/kg
  • 04.1.2.7 Candied fruit — 2,000 mg/kg
  • 04.1.2.8 Fruit preparations, including pulp, purees, fruit toppings and coconut milk — 1,000 mg/kg
  • 04.1.2.9 Fruit-based desserts, incl. fruit-flavoured water-based desserts — 1,000 mg/kg
  • 04.2.2.2 Dried vegetables (including mushrooms and fungi, roots and tubers, pulses and legumes, and aloe vera), seaweeds, and nuts and seeds — 1,000 mg/kg
  • 04.2.2.3 Vegetables (including mushrooms and fungi, roots and tubers, pulses and legumes, and aloe vera), and seaweeds in vinegar, oil, brine, or soybean sauce — 300 mg/kg
  • 04.2.2.4 Canned or bottled (pasteurized) or retort pouch vegetables (including mushrooms and fungi, roots and tubers, pulses and legumes, and aloe vera), and seaweeds — 1,000 mg/kg
  • 04.2.2.5 Vegetable (including mushrooms and fungi, roots and tubers, pulses and legumes, and aloe vera), seaweed, and nut and seed purees and spreads (e.g. peanut butter) — 1,000 mg/kg
  • 04.2.2.6 Vegetable (including mushrooms and fungi, roots and tubers, pulses and legumes, and aloe vera), seaweed, and nut and seed pulps and preparations (e.g. vegetable desserts and sauces, candied vegetables) other than food category 04.2.2.5 — 1,000 mg/kg
  • 04.2.2.7 Fermented vegetable (including mushrooms and fungi, roots and tubers, pulses and legumes, and aloe vera) and seaweed products, excluding fermented soybean products of food categories 06.8.6, 06.8.7, 12.9.1, — 2,500 mg/kg
  • 04.2.2.8 Cooked or fried vegetables (including mushrooms and fungi, roots and tubers, pulses and legumes, and aloe vera), and seaweeds — 1,000 mg/kg
  • 05.1.1 Cocoa mixes (powders) and cocoa mass/cake — 3,000 mg/kg
  • 05.1.2 Cocoa mixes (syrups) — 1,000 mg/kg
  • 05.1.3 Cocoa-based spreads, incl. fillings — 3,000 mg/kg
  • 05.1.4 Cocoa and chocolate products — 3,000 mg/kg
  • 05.1.5 Imitation chocolate, chocolate substitute products — 3,000 mg/kg
  • 05.2.1 Hard candy — 3,000 mg/kg
  • 05.2.2 Soft candy — 3,000 mg/kg
  • 05.2.3 Nougats and marzipans — 3,000 mg/kg
  • 05.3 Chewing gum — 10,000 mg/kg
  • 05.4 Decorations (e.g. for fine bakery wares), toppings (non-fruit), and sweet sauces — 1,000 mg/kg
  • 06.3 Breakfast cereals, including rolled oats — 1,000 mg/kg
  • 06.5 Cereal and starch based desserts (e.g. rice pudding, tapioca pudding) — 1,000 mg/kg
  • 06.8.1 Soybean-based beverages — 1,300 mg/kg
  • 07.1 Bread and ordinary bakery wares and mixes — 1,700 mg/kg
  • 07.2 Fine bakery wares (sweet, salty, savoury) and mixes — 1,700 mg/kg
  • 09.2 Processed fish and fish products, including molluscs, crustaceans, and echinoderms — 300 mg/kg
  • 09.3 Semi-preserved fish and fish products, including molluscs, crustaceans, and echinoderms — 300 mg/kg
  • 09.4 Fully preserved, including canned or fermented fish and fish products, including molluscs, crustaceans, and echinoderms — 300 mg/kg
  • 10.4 Egg-based desserts (e.g. custard) — 1,000 mg/kg
  • 11.4 Other sugars and syrups (e.g. xylose, maple syrup, sugar toppings) — 3,000 mg/kg
  • 11.6 Table-top sweeteners, including those containing high-intensity sweeteners — GMP
  • 12.2.2 Seasonings and condiments — 2,000 mg/kg
  • 12.3 Vinegars — 3,000 mg/kg
  • 12.4 Mustards — 350 mg/kg
  • 12.5 Soups and broths — 1,200 mg/kg
  • 12.6 Sauces and like products — 350 mg/kg
  • 12.7 Salads (e.g. macaroni salad, potato salad) and sandwich spreads excluding cocoa-and nut-based spreads of food categories 04.2.2.5 and 05.1.3 — 350 mg/kg
  • 13.3 Dietetic foods intended for special medical purposes (excluding products of food category 13.1) — 1,000 mg/kg
  • 13.4 Dietetic formulae for slimming purposes and weight reduction — 800 mg/kg
  • 13.5 Dietetic foods (e.g. supplementary foods for dietary use) excluding products of food categories — 1,000 mg/kg
  • 13.6 Food supplements — 5,500 mg/kg
  • 14.1.3.1 Fruit nectar — 600 mg/kg
  • 14.1.3.2 Vegetable nectar — 600 mg/kg
  • 14.1.3.3 Concentrates for fruit nectar — 600 mg/kg
  • 14.1.3.4 Concentrates for vegetable nectar — 600 mg/kg
  • 14.1.4 Water-based flavoured drinks, including "sport," “energy,” or "electrolyte" drinks and particulated drinks — 600 mg/kg
  • 14.1.5 Coffee, coffee substitutes, tea, herbal infusions, and other hot cereal and grain beverages, excluding cocoa — 600 mg/kg
  • 14.2.7 Aromatized alcoholic beverages (e.g. beer, wine and spirituous cooler-type beverages, low-alcoholic refreshers) — 600 mg/kg
  • 15.0 Ready-to-eat savouries — 500 mg/kg
CXS 192-1995 Table One, INS 951and 64 further provisionsretrieved 2026-09-07

What it is made from

A methyl ester of a dipeptide, made by joining the amino acids L-aspartic acid and L-phenylalanine, both produced by fermentation, and then methylating the result. It is digested into those components rather than excreted intact, which is why the phenylalanine declaration is required.

  • Vegan
  • Vegetarian
CAS registry number
22839-47-0
InChIKey
IAOZJIPTCAWIRG-QWRGUYRKSA-N
PubChem
CID 134601

Every name it appears under

64 recorded names. A label may use any of them.

E number

  • E951

INS number

  • 951

CAS registry number

  • 22839-47-0
  • 53906-69-7

As it appears in regulation

  • Aspartame

Other names

  • 1-Methyl N-L-alpha-aspartyl-L-phenylalanate
  • 1-Methyl N-L-alpha-aspartyl-L-phenylalanine
  • 3-Amino-N-(alpha-carboxyphenethyl)succinamic acid N-methyl ester
  • 3-Amino-N-(alpha-methoxycarbonylphenethyl) succinamic acid
  • Aminosweet
  • Asp-Phe methyl ester
  • Asp-phe-ome
  • Aspartam
  • Aspartame
  • Aspartame (e951)
  • Aspartame, L,L-alpha-
  • Aspartamo
  • Aspartamum
  • Aspartyl phenylalanine methyl ester
  • Aspartylphenylalanine methyl ester
  • Aspartylphenylalanine, Methyl
  • c-mer
  • Canderel
  • CCRIS 5456
  • Dipeptide sweetener
  • E 951
  • Equal
  • Gold, Hermesetas
  • H-Asp-Phe-OMe
  • HSDB 3915
  • Ins no.951
  • Ins-951
  • L-Aspartyl-L-phenylalanine methyl ester
  • L-Aspartyl-L-phenylalanyl methyl ester
  • L-Phenylalanine, L-alpha-aspartyl-, 2-methyl ester
  • L-Phenylalanine, N-L-.alpha.-aspartyl-, 1-methyl ester
  • L-Phenylalanine, N-L-alpha-aspartyl-, 1-methyl ester
  • Methyl aspartylphenylalanate
  • Methyl Aspartylphenylalanine
  • Methyl Ester, Aspartylphenylalanine
  • Methyl L-alpha-aspartyl-L-phenylalanate
  • methyl L-alpha-aspartyl-L-phenylalaninate
  • Methyl L-aspartyl-L-phenylalanine
  • Methyl N-L-alpha-aspartyl-L-phenylalaninate
  • N-L-ALPHA-ASPARTYL L-PHENYLALANINE 1-METHYL ESTER
  • N-L-alpha-Aspartyl-L-phenylalanine 1-methyl ester
  • N-L-alpha-Aspartyl-L-phenylalanine methyl ester
  • Nutrasweet
  • Pal Sweet
  • Palsweet Diet
  • PME
  • Sanecta
  • Sladex
  • Sweet dipeptide
  • Tri Sweet
  • Tri-sweet
  • TriSweet
  • Z0H242BBR1
  • Zero-cal

Systematic names

  • (3S)-3-amino-3-{[(2S)-1-methoxy-1-oxo-3-phenylpropan-2-yl]carbamoyl}propanoic acid
  • (3S)-3-amino-4-[[(2S)-1-methoxy-1-oxo-3-phenylpropan-2-yl]amino]-4-oxobutanoic acid
  • (3S)-3-azaniumyl-4-(((2S)-1-methoxy-1-oxo-3-phenylpropan-2-yl)amino)-4-oxobutanoate
  • (S)-3-Amino-4-(((S)-1-methoxy-1-oxo-3-phenylpropan-2-yl)amino)-4-oxobutanoic acid
  • Succinamic acid, 3-amino-N-(alpha-carboxyphenethyl)-, N-methyl ester, stereoisomer

Hazard reference values

Values set by assessing bodies. A body that has not set a value is not listed here.
TypeValuePopulationAssessed byOpinion
ADI40 mg/kg bw/dayconsumersEFSAnot identified in the dataset

Evidence and how bodies read it

How different bodies read the evidence

Positions are paraphrased in each body's own framing. Where they differ, both stand; this site does not adjudicate between them.

  1. IARC 2023

    Classified aspartame as Group 2B, possibly carcinogenic to humans, on limited evidence for hepatocellular carcinoma in humans. IARC classifies hazard — whether an agent can cause cancer in some circumstances — and does not assess the risk at actual intakes.

    Action taken: Hazard classification issued

    Source document

  2. JECFA 2023

    Reviewed the same evidence as a risk assessment and reaffirmed the acceptable daily intake of 40 mg per kg of body weight per day, finding no sufficient reason to change it. The two conclusions are not contradictory: they answer different questions.

    Action taken: Acceptable daily intake reaffirmed

    Source document

Sources for this page

  • ecfr retrieved 2026-09-07
  • gsfa retrieved 2026-09-07

Full licence terms and publisher details on Sources. How this page is built and updated: Method.

Machine-readable:/api/v1/additives/aspartame.json